I am trying to configure our 3 Netvanta 3140's to use our gateway 3140 as an NTP server since all network traffic has to flow through that gateway to get to the internet. The rest of our routers connect to the gateway via a direct fiber connection on a sub-interface and normal network traffic works just fine. The issue is that when I configure our routers as such:

ntp peer 192.168.41.29 normal-sync prefer

or

ntp peer 192.168.41.29 normal-sync version 3 prefer

we get the error in the Title above and the output of "show ntp association" is as below:

Address ref ID st when poll reach delay offset disp

VRF: -DEFAULT-

~192.168.41.29 -Unavailable- 16 455 64 0 0.00 0.00 16000.00

On the main router we have the following configuration:

ntp source gigabit-ethernet 0/1

ntp master 2

ntp peer 0.us.pool.ntp.org normal-sync version 3 prefer

Is there anything else we should be looking at in order to ensure our other 3 routers can connect to this gateway? No firewall is configured on any of the routers.